An individual with a personality marked with superficial charm, habitual lying, no regard for others, showing no remorse after hurting others, having no shame for outrageous and objectionable behavior, impulsivity, inability to form relationships and take responsibility, failure to learn from punishment, lack of empathy and conscience, and need for excitement. Also referred to as antisocial personality. While popular lore holds that the psychopath, with his diminished conscience, is able to defeat PDD testing, all research has found that the guilty psychopath is no different from guilty non-psychopaths in being detected by the polygraph. See: Barland & Raskin (1975); Raskin & Hare (1978); Patrick & Iaconno (1989).